RCC: Ultra-sensitive solid-state magnetometer

Main article: Human brain

2021: Presentation of an ultra-sensitive solid-state magnetometer

A team of researchers from the Russian Quantum Center, the Skolkovo Institute of Science and Technology and the Higher School of Economics presented an ultra-sensitive solid-state magnetometer and experimentally applied it to magnetoencephalography, a technology for measuring electrical activity in the brain. This became known on August 10, 2021.

The main quality of magnetoencephalography (MEG) in comparison with other methods of studying the electrical activity of the brain is high accuracy: biological tissues are transparent to magnetic fields. However, for August 2021, MEG is available only in a small number of laboratories around the world, which is due to the high cost and complexity of producing MEG systems that use extremely cold liquid helium or, conversely, heated to high temperatures. gas

The sensor developed by the Russian Quantum Center based on an iron-yttrium grenade film has become a solid-state ultra-sensitive magnetometer operating at room temperature. A system built on the basis of a quantum sensor has a higher sensitivity and makes it possible to record even weak or deep electrical sources of the brain. A large dynamic range will potentially reduce the degree of magnetic protection, which will significantly reduce the price of both the device itself and the infrastructure necessary for research.

An experimental study of the applicability of sensors was carried out by employees of the Skolkovo Institute of Science and Technology and the Higher School of Economics. It was based on the registration of a simple brain signal - alpha rhythm, which represents sinusoidal currents arising in the occipital region of the brain. The successful registration of alpha rhythm by the developed magnetometer is validated using other methods.

In the future, scientists plan to consider various sensor locations - including a flexible connection fixed around the head to most effectively localize the electrical activity of the cerebral cortex. In general, the results justify the need to further study the technology and gradually create a MEG system based on fully solid-state sensors. The launch of such a device will be an important step in the development of areas of non-invasive neuroimaging and non-invasive neurointerfaces.

The development of this magnetometer began by Peter Vetoshko, the technical director of the project, back in the mid-90s. Interest in MEG systems in the world is constantly growing: if in 2017 the market was estimated at $600 million, then by 2025 analysts predict an increase to $1.3 billion. It is important to note that despite the similar principles of operation of this quantum sensor and the classical ferrosond, quantum exchange interaction made it possible to register the value of the magnetic field 1000 times lower than when using traditional solutions. We see that the device is ideal for solving problems related to the study of the brain. Moreover, with this level of sensitivity, our sensor retains all the advantages of traditional ferrosonds and can be considered a universal magnetometer, - said Maxim Ostras, project manager at the Russian Quantum Center.

Even the first prototype of the developed magnetometer in some cases shows a higher sensitivity in the context of magnetoencephalography compared to existing systems. Coupled with the simplicity and solid-state nature of the sensor, this suggests an optimistic future for systems based on this technology. Of course, there is still a lot of work to be done. It is necessary both to continue physical research and to develop a new mathematical apparatus for the most efficient processing of the magnetometer signal of this type, taking into account its specifics, "said Nikolai Koshev, senior lecturer at the Skolkovo Institute of Science and Technology.

With the sensors presented, given their potentially low cost and reliability, we can hope that in the near future magnetoencephalography technology will become available to a larger circle of patients, doctors and researchers who will get their hands on a device for functional mapping of the brain, capable of localizing sources of neuronal activity and neural networks with millimeter accuracy. This will increase the quality of medical care, the accuracy of diagnostics of a number of neurological disorders, including epilepsy and will give an additional impetus to research into the mechanisms of brain function in normal and pathology, - said Aleksei Osadchy, director of the Center for Bioelectric Interfaces at the Higher School of Economics.

See also

Electroencephalography (EEG)